Several devices for blocking an opening in a damaged wall, a ceiling, or a similar structure, have been reported in prior art. The damage may have been caused by an accident or by the removal or relocation of a toggle screw or an electrical outlet. The resulting holes, with diameters which can range from one-half of an inch to two or more inches, present a special problem. Unlike very small holes which can be patched over by the deposition of a settable material, or very large holes which can receive an insert cut from wall board or a similar material, medium-sized holes need a backing for patch filler such as plaster while it is being put into place. Most of the suggested devices include backing plates for the settable material, which are manoeuvered into position by special tools and/or complicated means. A number of systems include expansion members which are inserted through the holes and opened out at the rear of the wall, such as, for instance, the umbrella-type shaft of U.S. Pat. No. 3,325,955, or the folded hinge plate of U.S. Pat. No. 3,690,084 which is to be opened by pulling a drawstring. These particular devices are not only expensive to manufacture, but liable to introduce complications which offset any advantages to be gained from such construction. Other references of interest include U.S. Pat. No. 2,638,774, 2,997,416, 3,295,285 and 3,834,107. In several devices suggested by the prior art, metal screws or fasteners which hold the backing plates in place, project outwardly from the damaged wall and must be cut or filed off after the hole has been filled. Such operations are cumbersome and moreover, likely to dislodge the plaster which has been deposited in the hole. Moreover, after removal of the projecting part, another plaster deposit has to be applied to cover the severed surface.
The present invention provides a device for, and method of, repairing an opening in a damaged wall portion of a double-walled structure which overcomes the limitations of the prior art. More particularly, it provides an economical and easy to use plug device which is insertable into an opening and which includes a surface on which a patching material may be deposited. The plug device requires no special tools for installation. It is firmly anchored to the opposite wall to prevent shifting during the hardening of the patch material. No steps are required subsequent to the disposition of the patch material. The device can be used for holes of various depths and with various grades of roughness in the surrounding or backing wall structures.
In accordance with the invention, a cylindrical plug, made from plastic foam material, is composed of two sections of a predetermined, but unequal length, which are held in end-to-end relationship. The boundary between the two sections is defined by an annular cut-through region to provide a break away line thereat. Pressure sensitive adhesive can be provided on the distal end of the longer of the two sections. As the plug is inserted into the hole and pushed against the inside surface of the opposing wall, the adhesive contact holds it firmly against displacement and rotation. Once the plug has been put into place, the shorter of the two sections is broken off at the weakened boundary region, and the exposed surface of the longer section, positioned inwardly of the damaged wall, forms a backing for a patch filler material such as plaster, spackle or the like. The plug need not fit the hole shape exactly. In a preferred embodiment a coextensive portion of resilient material is attached to the adhesive material at the distal end of the longer plug section and includes, at its free end, another layer of pressure sensitive adhesive material, to be engaged by the surface of the opposite wall. The interposition of the resilient material serves to facilitate placement of the plug against a rough inner surface provided on wall structures of this kind. The plug can be provided in several diameters and in several lengths. It can be made to patch hollow doors as well as other double walls.